NVIDIA RTX PRO 4000 Blackwell vs RTX PRO 4500 Blackwell Workstation Edition: 24 or 32 GB

RTX PRO 4000 vs RTX PRO 4500 Blackwell in one decision table

The NVIDIA RTX PRO 4000 Blackwell and the NVIDIA RTX PRO 4500 Blackwell Workstation Edition are neighbours in NVIDIA's workstation line. The RTX PRO 4000 has 24 GB of memory at 672 GB/s and takes one slot at 145 W. The RTX PRO 4500 Workstation Edition has 32 GB at 896 GB/s and takes two slots at 200 W. Order the smaller card when slots or power are short or several GPUs share a tower, and the larger one when a single scene or model needs more than 24 GB.

A third card carries the number 4500. It stands in the table so that an enquiry names the right part.

NVIDIA datasheets 5323450 (June 2026), 5108623 (April 2026) and 5192801 (April 2026).

We supply all three across the EU; tell us which card you are weighing and for which workstation or server and we reply with a written quote within one business day. This page compares the two workstation cards and comes to the Server Edition near the end.

Where the two workstation cards differ in NVIDIA's datasheets

NVIDIA datasheets 5323450 (June 2026) and 5108623 (April 2026); adapters from NVIDIA's quick start guide for RTX PRO Blackwell cards; the last row is our arithmetic, explained below.

NVIDIA announced both cards on 18 March 2025. The larger one was called RTX PRO 4500 Blackwell then and carries the addition Workstation Edition in its datasheet of April 2026, while drivers and release notes still use the short name.

By our arithmetic the RTX PRO 4500 Workstation Edition has 17 per cent more CUDA cores and a third more memory and memory bandwidth, for 38 per cent more board power. Its datasheet gives 51 TFLOPS of single precision and 1,617 AI TOPS. For the RTX PRO 4000 NVIDIA's own documents disagree. NVIDIA's datasheet (June 2026) gives 1,178 AI TOPS and 37 TFLOPS, its product page 1,290 and 40. AI TOPS is on both cards a theoretical FP4 figure with sparsity and no measured rate, so these numbers show the order of the two cards and little more.

Puget Systems' professional GPU roundup of 18 December 2025, run on a Ryzen 9 9950X3D, tested each card against the Ada card of the same number. The RTX PRO 4000 was 83 per cent ahead of the RTX 4000 Ada in V-Ray GPU and 40 per cent in Blender Cycles; the RTX PRO 4500 Workstation Edition was 73 and 50 per cent ahead of the RTX 4500 Ada. The baselines differ, so no ratio between the two Blackwell cards follows from those figures.

A rough direct comparison comes from Blender Open Data, where users submit their own runs. Read on 10 November 2026, the median of 17 submissions for the RTX PRO 4500 Workstation Edition on Blender 4.5.0 was 8,486.57 samples per minute, and the median of 40 submissions for the RTX PRO 4000 Blackwell was 6,255.71. On Blender 5.2.0 the medians were 9,185.89 from 5 submissions and 6,772.89 from 17. That is about 36 per cent more on either version, by our arithmetic. The data are crowd-sourced, OptiX and CUDA runs are pooled, and processor, driver and operating system are not controlled.

24 GB vs 32 GB for language models, image models and rendering

The 8 GB between the cards matter most where a file has to sit in GPU memory as a whole.

Language models. Our sizing rule takes 0.9 times the memory the driver reports and subtracts 3 GiB; the rest is the budget for model weights plus KV cache. That gives 18.5 GiB on the 24 GB card and 25.7 GiB on the 32 GB card. For the reported memory we scale the 95.6 GiB that the driver shows on the 96 GB card, which is an assumption; what the driver shows on the delivered card is what counts. The file sizes were read on Hugging Face on 10 November 2026.

our arithmetic by the sizing rule, not a measurement; file sizes from the publishers' Hugging Face repositories, read 10 November 2026. "Left" is the room for KV cache, that is for context.

Two files of 22 to 24 GiB fit only the 32 GB card. And every file that fits both cards has about 7 GiB more room for context on the larger one, which decides how long a document can be or how many requests run at once. Qwen3.8-27B in FP8 does not fit the 32 GB card either: its 28.75 GiB exceed 0.9 times the memory the driver reports, 28.7 GiB by our scaling. Four other files of 26.0 to 28.2 GiB, among them Ministral 3 14B in BF16 and Granite 4.2 30b in FP8, are above our 25.7 GiB budget, and we do not plan on them. Our article on local LLMs on the RTX PRO 4000 Blackwell lists the files for the 24 GB card.

Image models. By our arithmetic, which sets the file sizes against nine tenths of the card's memory, Stable Diffusion 3.5 Large fits a 24 GB card together with its text encoders only when the T5 encoder is the FP8 file (21.41 GiB for the pipeline); with the FP16 encoder the pipeline is 25.97 GiB and needs the 32 GB card. The BF16 file of FLUX.1-dev, 22.17 GiB for the model alone, has to be partly loaded from system memory on 24 GB and fits 32 GB without its text encoder. Licences limit both: FLUX.1-dev is under a non-commercial licence, and Stable Diffusion 3.5 under the Stability AI Community License, whose conditions need reading. FLUX.2 klein 4B under Apache 2.0 fits either card with everything loaded. Our guide to ComfyUI on RTX PRO 2000, 4000 and 4500 has the full table.

Rendering and CAD. Chaos states for V-Ray GPU that the whole scene has to fit into GPU memory and that, with cards of different memory, it should fit the smallest one. The Cycles documentation of Blender says that each GPU can only access its own memory. A scene of 28 GB therefore needs the 32 GB card, and four 24 GB cards do not hold it either. The requirement pages of application makers that we read on 10 November 2026 do not separate the two cards: their GPU memory figures end at 16 GB, for example for the advanced AI tools of DaVinci Resolve Studio 21.2 (readme of 4 November 2026) and for the high-end tier of Lumion 2026.

Four RTX PRO 4000 in the slots of two RTX PRO 4500 Workstation Edition cards

Among the RTX PRO Blackwell cards on NVIDIA's desktop line-up page of 8 September 2026, only the RTX PRO 4000 is listed as single slot. Four of them take the slot widths of two RTX PRO 4500 Workstation Edition cards.

our arithmetic from NVIDIA datasheets 5323450 (June 2026) and 5108623 (April 2026) and NVIDIA's quick start guide for RTX PRO Blackwell cards.

The four-card build has half as much memory again in the same slots, twice the display outputs and twice the video engines, at 180 W more. Its limit is the memory of one GPU. Each card has its own 24 GB, and NVIDIA's datasheets list no NVLink for either card. By our reading the four-card build suits four users, four jobs or four copies of a model that fits one card, while two RTX PRO 4500 Workstation Edition cards hold less memory in total and the larger single file. How a serving engine splits one model over several cards, and what that costs over PCIe, is worked through on our page on four RTX PRO 4000 in one workstation and in the comparison of several RTX PRO 5000 or 4500 against fewer RTX PRO 6000.

If a tower is to take several cards, send us the workstation model, the free slots and the largest file or scene you load, and our quote names the layout that fits.

Power cable, card length and the workstation

Both cards use one PCIe CEM5 16-pin connector. The adapter in the box differs: NVIDIA's quick start guide lists one from a single 8-pin PCIe cable for the RTX PRO 4000 and one from two 8-pin PCIe cables for the RTX PRO 4500 Workstation Edition. With the adapters, one spare 8-pin lead feeds the smaller card, and the larger one needs two. Neither datasheet names a power-supply wattage. Take the board power, 145 W or 200 W per card, add it to what the system draws today and check the total against the rating that the system's maker gives for its power supply. Our overview of RTX power connectors covers the cables of the whole range.

The larger card is one inch longer, 10.5 in against 9.5 in, about 267 mm against 241 mm by our conversion; NVIDIA gives inches only. Both are full height with active cooling. For system memory the quick start guide sets the GPU memory as the minimum and recommends double: 24 GB and 48 GB per RTX PRO 4000, 32 GB and 64 GB per RTX PRO 4500 Workstation Edition.

What is the same on both cards

• Displays. Four DisplayPort 2.1b outputs; the datasheets list four displays at 3840 × 2160 and 165 Hz or two at 7680 × 4320 and 100 Hz. Neither card has an HDMI output.
• Video. Two NVENC and two NVDEC engines; NVIDIA's support matrix of 16 October 2026 lists AV1 and 4:2:2 encoding and an unrestricted number of sessions for both.
• Platform. PCIe 5.0 x16, GDDR7 with ECC, compute capability 12.0 with FP4 and FP8 support.
• Sync board. NVIDIA's RTX PRO Sync page of 15 October 2026 and the sync table of the 621.14 release notes list both cards.
• Drivers. Both are in the current R580, R595 and R620 releases. NVIDIA's product lists, as we read them, first name both cards in the same Linux releases: 570.169, 575.64 and 580.65.06 in their branches.
• Certification lists. Dassault's SOLIDWORKS 2026 list, read 10 November 2026, has rows with desktop workstations for both names; a row certifies one computer model with one card and one driver.
• Virtualisation. Neither card is on NVIDIA's vGPU list of 2 October 2026.

MIG is the one feature on which the documents are unclear. The RTX PRO 4000 is not in NVIDIA's MIG guide. NVIDIA's MIG guide lists an RTX PRO 4500 Blackwell without naming the edition; the Workstation Edition datasheet does not mention MIG. We would not plan a workstation around it. Our overview of MIG and vGPU on RTX PRO and Ada cards has the details.

The names differ in one respect. A laptop GPU called RTX PRO 4000 Blackwell Generation, with 16 GB, and a 70 W SFF Edition of the RTX PRO 4000 exist; NVIDIA lists no laptop GPU with the number 4500.

The RTX PRO 4500 Server Edition is a third card

The NVIDIA RTX PRO 4500 Blackwell Server Edition shares the 32 GB of GDDR7 and the 10,496 CUDA cores of the Workstation Edition, and it is built for a different machine. It is a passive single-slot card of full height and full length that relies on the airflow of a server, at 165 W with 800 GB/s of memory bandwidth. It has three NVENC and three NVDEC engines, MIG with up to two instances of 16 GB and vGPU support from release 20.0, and NVIDIA's documents state no display output for it. It has no fan of its own and belongs in a server whose maker lists it.

The card is described on our page to buy the RTX PRO 4500 Server Edition and in the RTX PRO 4500 Blackwell Server Edition article. Two existing comparisons set it against the cards of this page: RTX PRO 4500 Workstation Edition or Server Edition and single-slot GPUs for AI, RTX PRO 4000 or RTX PRO 4500 Server Edition.

Which card for which case

our summary of the sections above.

Before a tower gets several cards, check its maker's card list. Where 32 GB is not enough either, the next step is the subject of RTX PRO 4500 vs RTX PRO 5000 Blackwell, and the step below the smaller card is in RTX PRO 2000 vs RTX PRO 4000 Blackwell.

The cards have their own pages: buy the RTX PRO 4000 Blackwell with its specs, and buy the RTX PRO 4500 Blackwell with its 32 GB spec page. If the choice is still open, name the application and the chassis, and we quote the card that fits, or both.

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